Brink RC, Homans JF, Schlösser TPC, et al. - Researchers sought to define the longitudinal rotation axis around which individual vertebrae rotate. In addition, they examined thoracic adolescent idiopathic scoliosis (AIS) patients to ascertain the various extra- and intravertebral rotation patterns in them, for better understanding of the 3D development of the rotational deformity. They assessed 70 high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°–109°) and identified that the longitudinal rotation axis was localized posterior to the spine for all levels, from which the vertebrae rotate away from the midline. At the apex, the distance between this axis and the spine is minimal and this distance increases gradually to the neutral zones. Smaller amounts of intravertebral rotation and local mechanical torsion, which increases toward the apical region, accompany the vertebral axial rotation. For a better understanding of the 3D pathoanatomical development of AIS and better therapeutic planning for bracing and surgical intervention, they suggest assessing the altered morphology and alignment as crucial.